标题：A DFT study on the thermal decomposition of 2-chloroethylsilane
作者：Bei, Y.;Liu, Q.;Feng, S.
作者机构：[Bei, Y] Key Laboratory of Special Functional Aggregated Materials, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, C 更多
通讯作者地址：[Feng, SY]Shandong Univ, Sch Chem & Chem Engn, Minist Educ, Key Lab Special Funct Aggregated Mat, Jinan 250100, Peoples R China.
关键词：2-Chloroethylsilane;Ab initio calculation;Density functional theory;Thermal decomposition
摘要：The thermal decomposition of 2-chloroethylsilane (H _3SiCH _2CH _2Cl) was investigated by density functional theory (DFT) method at the B3LYP/6-311G(d,p) level. The structures of reactants, transition states, and products were located and fully optimized at the B3LYP/6-311G(d,p) level, and the geometries of various stationary points and harmonic vibrational frequencies were calculated at the same level. The reaction paths were investigated and confirmed by intrinsic reaction coordinate calculation at the B3LYP/6-311G(d,p) level. The results showed that the thermal decomposition of 2-chloroethylsilane could happen in one pathway. The chlorine migrated with negative charge from the β-carbon toward the silicon resulting in the C _β-Cl bond dissociated, then the C _α-Si bond length increased passing through a four-centered transition state to form chlorosilane (H3SiCl) and ethene (CH _2=CH _2). The B3LYP/6-311G(d,p) barrier for the decomposition reactions was 177.0 kJ mol ~(-1). The halogen-substituent effects on 2-chloroethylsilane showed that the less negative charges on β-carbon atoms made the reaction more likely to occur. Changes in thermodynamic function, equilibrium constant, and reaction rate constant in Eyring transition state theory were calculated over a temperature range of 400-1,500 K.